(1) Field of the Invention
The present invention relates to a bar code reader and to a method of reading a bar code. More specifically, the invention relates to a bar code reader which is capable of scanning and reading a bar code by employing, for example, a handheld laser scanner or the like, and to a method of reading a bar code.
(2) Description of the Related Art
A portable terminal device called a handheld terminal has been developed in the physical distribution-related services such as stock management (ordering of goods, stocktaking), etc., for the purpose of grasping and collecting data at a moment when the data are produced. The data collected by the handheld terminal are sent to a host computer (personal computer, office computer, etc.) installed in an office where they are analyzed and processed to be used as determined by the management (policy of business, service for customers, management of goods, etc.).
Furthermore, a bar code reader has been widely utilized as a means for inputting data to the handheld terminal. Inputting the data relying upon bar codes has been extensively employed since it is quicker and easier than inputting the data by hand through a keyboard and is more accurate.
The bar code reader will usually be a touch scanner or a pen scanner using a light-emitting diode, but a handheld laser scanner has been widely used. This device contains a transmitter, a vibrating mirror (the angle of vibration of the vibrating mirror being constant), a receiver, a decoder, an interface and the like. Therefore, it becomes difficult to correctly read the data when a plurality of bar codes are included in a scanning range of the scanning beam. This conventional bar code reader will be described later in the description of the preferred embodiments with reference to the drawings.